Tracking a Signal
by TARDISgirl192
Summary: While trying to figure out how to relieve his boredom, the Doctor discovers a strange energy signature and decides to see where it leads him. What he finds at the source isn't what he expected.


**A/N: This is a prequel to my other fic Sorry, Wrong Universe! You don't have to read Sorry, Wrong Universe! to understand this fic. And just to be safe, there are spoilers for TRON:Legacy. **

**Anyway, enjoy the story.**

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><p>The Doctor sat in the captain's chair and stared up at the ceiling, utterly bored and at a loss as to what to do. Jack had gotten a call from Torchwood and was off fighting—well, the Doctor couldn't remember and Rose was visiting a friend on Pete's world.<p>

The more the Doctor thought about it, the more he thought it was a good that he was away from Rose for a bit. Truth be told, the Doctor was tired of walking on eggshells around her, lest he cause another fight.

As his thoughts turned to his and Rose's relationship, the console started to beep. The Doctor jumped up and ran around the console, thrilled to have something to do. The Doctor stopped at the monitor to check the readout. The energy signature that the TARDIS picked up was faint and hailed from an unknown source.

"Okay old girl, I'm going to need everything you've got," the Doctor said as he flipped a switch. The TARDIS shook as she tracked the signature back to where it came from. He grinned as he fell to the ground, a sign that the TARDIS had landed.

* * *

><p>It was Saturday, which meant a day off for Sam Flynn and a chance to spend time with his favorite ISO.<p>

Sam was hard at work preparing breakfast while Quorra sat on their sofa watching TV. Quorra flipped through the channels before she happened upon a show with an odd, yet catchy theme tune. Quorra rocked in time to the music and decided to find out more about this "Doctor Who".

"Sam, what's this?" she asked as the title of the episode, New Earth, appeared on the screen. Sam walked over to get a better look at the show.

"That's Doctor Who. I think you'd like it." Quorra watched for a few minutes before asking,"Is it like what you showed me yesterday?"

Sam smiled as he walked back to the kitchen."No, what we watched yesterday was a newscast. Newscasts are non-fiction-well, most of the time anyway. Doctor Who is fiction, which means it isn't real."

Quorra sighed and said,"I was hoping to meet this Doctor guy."

Out of no where, an odd grinding noise filled the room before a familiar blue box materialized near the sofa. Quorra turned to look at the source of the noise as Sam dropped the spatula he held in shock. Both stayed frozen as the double doors opened. A man in a blue suit and brown trench coat stepped out of the TARDIS and smiled at Quorra.

"Hello, I'm the Doctor," the Doctor said as he pulled the sonic screwdriver out of his pocket and started to scan the area.

"Hmm, Earth, North American Continent, United States. I rarely get to the US, so this'll be a nice change of pace," the Doctor said to himself as Quorra continued to stare at him. She then looked from the Doctor to the TV, then back to the Doctor. Quorra turned to look at Sam and pointed at the Doctor. She then shifted into a kneeling position on the sofa before she reached out and poked the Doctor's forearm. Quorra jerked her hand back when she realized he was real.

"Did I land in a pocket dimension populated by mutes?" the Doctor asked with a puzzled expression as he watched Quorra stare at him. He glanced passed her at the TV and frowned.

"Whose the handsome bloke on the telly?" he asked as he walked around the sofa and sat down next to Quorra.

"Oh, that's you." Quorra replied in a matter-of-fact tone. The Doctor looked shocked but didn't take his eyes off the screen.

"That can't be me, I'm right here, though—wait, I remember this! The hospital, the cat nuns, New New York!" The Doctor frowned and turned to Quorra.

"Why is a past adventure of mine being broadcast on television?"

"Because in this universe, you're a character on a TV show," Sam said as he walked towards the sofa. The Doctor stood up and turned face Sam.

"So you're telling me that I'm fictional?"

"Yes. In this universe, you, the Master, the Daleks, the Cybermen don't exist apart from being elements of a TV show."

The Doctor's face held an odd mixture of relief and uneasiness. He sat back down and sighed.

"If it makes you feel better, I wasn't technically real not too long ago." The Doctor glanced at Quorra with a look of surprise. He pulled the sonic screwdriver out of his pocket and scanned her.

"Hmm, three strands of DNA. Don't see that very often on earth—well, my earth anyway," the Doctor paused and put the screwdriver away." So, where exactly do you come from then?"

Sam and Quorra exchanged looks before they both said,"A computer system."

The Doctor opened his mouth to say something, then closed it, apparently at a loss for words.

"I wasn't expecting an answer like that. The closest I've come to programs like that was when humans were digital downloads, and of course that one time in the library," the Doctor said after some time had past.

"I used to live in a place called the Grid. It was nice, except for the time when I was being hunted down by the other programs," Quorra said. The Doctor frowned.

"Why were they hunting you?" Sam took that as his cue to speak up.

"Quorra is an ISO, a computer program that spontaneously generated within the computer system. From what my dad said, there used to be hundreds of them populating the Grid. My dad's program went rogue and took over the Grid, however, then set about deleting all the ISOs. My dad saved Quorra, but the others weren't so fortunate. She is the last of her kind."

The Doctor nodded, then said as he glanced from Sam to Quorra,"I can sympathize, as I'm sure you know."

A silence settled over the room before a thought dawned on the Doctor. He got up quickly and started to scan the area again while he changed the setting on the sonic screwdriver. Sam and Quorra once again stared in wonder at the Doctor's actions. Before either one of them could ask for an explanation, the Doctor said,"There was this faint energy reading, almost like a signal, that the TARDIS picked up. I think the energy might be coming from the Grid."

"The Grid that Quorra came from wouldn't be drawing power like that," Sam said as he held up the USB drive that hung around his neck."This is where it is now. The only place that would draw energy like that would be ENCOM. The Grid there was copied to make this one."

The Doctor thought for a moment as he tapped his forehead with the sonic. "I have an idea, and it involves getting the TARDIS to ENCOM. Do you think it will be difficult to get into the building?"

Sam shook his head, then smiled and said," It shouldn't be a problem."

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><p>A large flat-bed truck typically used for towing cars pulled up to the guard's station that stood between the ENCOM parking lot and the street. The window on the driver's side drifted down. To the security guard's surprise, Sam Flynn was behind the wheel. Sam was about to say something, but was interrupted by the Doctor, who was sitting to the far right of him.<p>

"I have this covered, just use this." Sam frowned as the Doctor handed him the psychic paper.

"The psychic paper won't be necessary." The Doctor looked a little sad as Sam reached across Quorra and gave him the psychic paper back.

"Good day, Mr. Flynn. I didn't expect you to come in today."

"I had some unexpected business come up." The guard nodded and pushed a button on the wall near him. The gate lifted and Sam nodded his thanks before he drove forward.

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><p>After they found a suitable entry point for the truck, Quorra, Sam, and the Doctor piled out of the vehicle and set to work getting the the space ready.<p>

The Doctor approached the laser apparatus, a hint of wonder and excitement on his face. "Is this what we'll be using to get to the Grid?"

"Yes. The laser will break us down and convert us into bits before transferring us to the computer," Sam said as he and Quorra started to connect the needed computer equipment together.

After a few minutes, Sam stepped away from the system and walked to the back of the truck before he said,"Now would be a good time to unload the TARDIS."

The Doctor nodded and moved to undo the chains around the TARDIS as Sam got into the truck. The bed of the truck raised up off the frame before it moved backwards and inclined. Under the Doctor's watchful eye, the TARDIS slid gently off the bed and onto the floor.

"Everything's ready," Quorra said as from behind the computer setup as Sam stepped out of the truck. Sam gestured for the Doctor to follow him as he walked to where Quorra was.

"Now all that has to be done is to input the physical information for the TARDIS into the computer," Sam said before the Doctor moved to type at the computer. The Doctor hit the enter key after several keystrokes.

"You're going to want to pay attention to this part," Quorra said with a smile as the laser powered up and fired a beam at the TARDIS. A white outline formed around the TARDIS as little cubes of it were taken one-by-one into the computer at a blurred pace. Before long, the TARDIS was no where to be seen.

The Doctor stood frozen for a moment before he ran toward the spot where the TARDIS, a surprised grin on his face.

"That was brilliant; I want to go next!" Sam nodded and changed the physical information from box-like to humanoid. The Doctor stood perfectly still as Sam gestured that it was ready. The laser fired again and in seconds the Doctor was being broken down into ones and zeros. Before anyone could blink, the Doctor was gone, sent hurling through the system at high speeds.

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><p>The next thing the Doctor saw was a vast cybernetic landscape. He stood, mouth agape, as he took in the digital world around him. The Doctor walked forward and realized that the TARDIS was to his left. A noise behind him signaled that someone else had arrived. The Doctor turned to see who it was, though he wanted to stare at the surrounding area more.<p>

"So, what do you think?" Sam asked as he and Quorra walked up to him.

"This place is amazing, and I don't often say that about most places."

Sam nodded before he said,"How about Quorra and I show you around before you head back to you own universe."

"Allons-y."

"While we're here, I'd like to find out if this one program is still around. Wanna help, Doctor?"

The Doctor thought for a few minutes before he said,"Yeah, I'll help. What's the program's name?"

Sam looked towards the city off in the distance and said," His name is TRON."


End file.
